Omega Dental Care Blog

Why Do I Get Cavities? An Introduction to Biofilm Imbalance

There are many reasons why we suffer from cavities, and the answer can be different for each individual. The most common answer that may be given to you is, “you have the bacteria that causes dental cavities”. In reality, almost all of us probably do have this significant contributor to tooth decay in our mouth. Dental Caries is a disease that causes cavities in our teeth. This disease is an imbalance of the “biofilm”. Biofilm is technically the very sticky layer of bacteria and other microbes on your teeth. We all have a biofilm on our teeth. A balanced biofilm with good bacteria is protective, but biofilm imbalance is what can lead to problems. 

There are several reasons why your biofilm becomes dysfunctional or imbalanced. 

The most important driving factor in the destruction of a healthy biofilm is the pH of the biofilm. You probably know that pH indicates the acid or base status of a substance. For example, water has a pH of 7 (neutral) while lemon juice has a pH of around 2.5 (acidic). There is a critical acidic level ( at or below pH of 5.5), at which point bad bacteria will thrive and cavities will develop. If the pH stays above 5.5, a healthy biofilm will exist.

Another common factor that can cause the fast and furious change in our oral health is the lack of saliva known as “dry mouth”. Our saliva provides a bath for our teeth and oral mucosa. It provides many protective mechanisms to fight bacteria and helps maintain a good pH of the biofilm. Normal saliva flow is very important in the maintenance of healthy biofilm, as it provides protection from an overload of potentially harmful bacteria and other microbes. 

A third factor that influences our oral biofilm is, of course, Diet. Everytime we eat or drink, our oral pH drops. Remember the critical pH level of 5.5 for a sustained time and/or frequency? This relates to diet because the bad microbes feed when you are feeding and they create waste products that are acids. Acids dissolve minerals in our teeth. This process is accelerated by the duration and frequency of the exposure. Overtime, the biofilm becomes imbalanced and sick with bad bacteria.

Genetics can also influence the makeup of our biofilm. Although it is a more infrequent influencer, there are some genetic disorders that affect the formation and structure of teeth. “Soft enamel” can be genetic in nature if one of these genetic disorders is present. Yet, when evaluating the genetic component of dental disease, we must remember that dental disease in itself causes soft enamel. Genetics plays an important role in our susceptibility to many diseases, and it is no different when examining dental diseases.

Dental Disease can also be considered a "transmissible" disease. Parents, or other providers, can pass on their bacterial strains to children. Researchers have found that strains of bacteria in the mouth can be identical to that of your parents, or other care providers. This finding shows that bacteria is transmissible between family members, but does not indicate a genetic link.

Biofilm imbalance is at the core of dental disease. Biofilm contains bacteria and other microbes like yeasts and viruses. If you want to know whether your biofilm is healthy, just ask yourself if you get cavities. Cavities are the sign that your biofilm is imbalanced. If you are sure that your pH is good, diet and frequency of eating is balanced, and you have plenty of saliva (there is a caveat to this one which will be discussed in future articles), you may have too much biofilm on the teeth or an overload of the bad bacteria.


Thank you for reading this brief on dental caries (cavities). Please subscribe to our newsletter for future updates on this subject and what YOU can do about dental caries with the help of your dentist. In the meantime, consider these influencers of dental disease and determine possible reasons for your dental cavities.


Dr. Ann Soberay, D.D.S, Cariologist

Omega Dental Care, P.A.

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